I beg to differ about Glencore. Their primary interest lies in...

I beg to differ about Glencore. Their primary interest lies in the supply side, so a higher cobalt price would suit them to a T. Same goes for other players like Cobalt 27, all the other miners and explorers, even the DRC. To all of these, the higher the price of cobalt, the better it is for them. So they are with us, we are all on the same side as far as the price of Co is concerned, there is absolutely no doubt about it.
China, on the other hand, is another story. They have so much vested interest in the demand side that it really sticks out like a sore-thumb when they invest in the supply side. These are all macro players and we can only observe and act according to their movements, unfortunately.

But here's something interesting to observe. When the Co price cratered in mid-2016, from a high in late-2015, China Moly bought stakes in DRC cobalt in May-2016. That's almost right at the bottom of that Co price cycle ... coincidence or pure genius? Immediately after that, the Co price went on a massive bull run that ended in the current crash. Here's a link (deal done in May-2016, completed Nov-2016):
https://do not advertise external sites/Article/3602523/Freeport-announces-completion-of-Tenke-mine-sale-to-China-Moly-for-initial-265bn.html

Now, just last month Jan-2019, China Moly was at it again, buying more stakes in DRC cobalt:
http://www.mining.com/china-moly-ups-stake-giant-tenke-copper-mine-80/ 

I'm not sure about you, but I am firmly of the belief that China knows what it is doing. It does not rely on "coincidence".... that's how they ended up having such a strong economy! Love them or hate them, you have to admit they know how to run a successful economy. So, when they make a move into (or further into, in this case) a particular resource, you better be ready for that resource to boom! 
Next step is UP.... way UP...  for Co price based on this alone, IMHO!